In some aerospace applications, it may be desirable to secure structures to each other using a fastener. A fastener having a diameter which is greater than the diameter of a fastener opening provided in the structures to be secured may be forced into the fastener opening to achieve an interference fit of the fastener in the fastener opening. A lubricant such as cadmium, for example and without limitation, may be coated on the fastener shank to provide the necessary lubricity to insert the fastener in the fastener opening. In the case of composite structures and titanium structures, however, it may be desirable to use a sleeved fastener.
In order to reliably install a sleeved fastener into sleeve openings provided in the structures, it may be necessary to lubricate the shank of the fastener. In some applications, multiple lubricants may be applied to the fastener shank to lubricate the fastener shank in the sleeve. The lubricant(s) may be applied to the fastener shank and/or to the interior surface of the sleeve. The lubricants may electrically insulate the fastener from the fastener sleeve. In some applications, it may be desirable to enhance the electrical conductivity between the fastener and the fastener sleeve.
Even where a desired level of conductivity between the fastener and the fastener sleeve is achieved, however, additional issues may arise when the fastener and sleeve are assembled and result in incidental contact with other elements of the structure or assembly. Therefore, a conductive sleeved fastener assembly which provides an electrically-conductive interface between a fastener sleeve and the fastener while preventing incidental contact with other structural elements may be desirable for some applications.